A novel STM-assisted microwave microscope with capacitance and loss imaging capability

Imtiaz, Atif; Anlage, Steven M.

doi:10.1016/s0304-3991(02)00291-7

Cited by 58 publications

(56 citation statements)

References 22 publications

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“…The unique feature of our NSMM 23 (schematic shown in Fig. 1) is the use of a transmission line resonator made out of commercially available UT-085 coaxial cable.…”

Section: Experimentmentioning

confidence: 99%

Effect of tip geometry on contrast and spatial resolution of the near-field microwave microscope

Imtiaz

Anlage

2006

Journal of Applied Physics

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The Near-Field Scanning Microwave Microscope (NSMM) can quantitatively image materials properties at length scales far shorter than the free space wavelength (λ). Here we report a study of the effect of tip-geometry on the NSMM signals. This particular NSMM utilizes scanning tunneling microscopy (STM) for distance-following control. We systematically examined many commercially available STM tips, and find them to have a conical structure on the macroscopic scale, with an embedded sphere (of radius r sphere ) at the apex of the tip. The r sphere values used in the study ranged from 0.1 μm to 12.6 μm. Tips with larger r sphere show good signal contrast (as measured by the frequency shift (Δf) signal between tunneling height and 2 μm away from the sample) with NSMM. For example, the tips with r sphere = 8 μm give signal contrast of 1000 kHz compared to 85 kHz with a tip of r sphere = 0.55 μm. However, large r sphere tips distort the topographic features acquired through STM. A theoretical model is used to understand the tip-to-sample interaction. The model a email address: anlage@umd.edu 1 quantitatively explains the measured change in quality factor (Q) as a function of height over bulk Copper and Silicon samples.

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“…The unique feature of our NSMM 23 (schematic shown in Fig. 1) is the use of a transmission line resonator made out of commercially available UT-085 coaxial cable.…”

Section: Experimentmentioning

confidence: 99%

Effect of tip geometry on contrast and spatial resolution of the near-field microwave microscope

Imtiaz

Anlage

2006

Journal of Applied Physics

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“…SMM combines AFM with microwave signal analysis to measure a variety of sample properties including complex dielectric constant [49], sheet resistance [1,10] and tip sample capacitance [1113]. SMM has also been shown to be sensitive to magnetic domain structure [14] and photovoltaic response [15,16].…”

Section: Introductionmentioning

confidence: 99%

Advanced Characterization of Material Properties on the Nanometer Scale Using Atomic Force Microscopy

Fenner

et al. 2012

Acta Phys. Pol. A

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We report recent advances in material characterization on the nanometer scale using scanning microwave microscopy. This combines atomic force microscopy and a vector network analyzer using microwave tip sample interaction to characterize dielectric and electronic material properties on the nanometer scale. We present the methods for calibration as well as applications. Scanning microwave microscopy features calibrated measurements of: (1) capacitance with attofarad sensitivity. For calibration a well characterized array of capacitors (0.1 fF to 10 fF) is used. The method is applied to determine the dielectric properties of thin organic lms, (2) Semiconductor dopant density. Calibration is performed by imaging the cross-section of a standard sample with dierently doped layers (dopant stair case) from 10 16 atoms/cm 3 to 10 20 atoms/cm 3 .

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“…Recently, the SMM topographic spatial resolution has been significantly improved by combining this tool with a scanning tunneling microscope (STM) [6][7][8] or an atomic force microscope (AFM) [9]. An STM-SMM can obtain an atomic resolution image of highly ordered pyrolytic graphite (HOPG) by mapping the energy loss caused by the tunneling junction impedance [8,11].…”

mentioning

confidence: 99%

Near-field microwave imaging of inhomogeneous KxFeySe2: Separation of topographic and electric features

Takahashi

Imai

Maeda

2015

Applied Physics Letters

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It is important for modern scanning microwave microscopes to overcome the effect of the surface roughness. Here, we report microwave conductivity imaging of the phase-separated iron chalcogenide KxFeySe2 (x = 0.8, y = 1.6-2), in which electric conductivity-induced contrast is distinguished from topography-induced contrast using a combination of a scanning tunneling microscope and a scanning microwave microscope (STM-SMM). We observed the characteristic modulation of the local electric property that originates from the mesoscopic phase separation of the metallic and semiconducting phases in two different scanning modes: constant current (CC) mode and constant Q (CQ) mode. In particular, CQ scanning is useful because we obtain a qualitative image in which the topographic contrast is largely eliminated without degradation of the spatial resolution.

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A novel STM-assisted microwave microscope with capacitance and loss imaging capability

Cited by 58 publications

References 22 publications

Effect of tip geometry on contrast and spatial resolution of the near-field microwave microscope

Effect of tip geometry on contrast and spatial resolution of the near-field microwave microscope

Advanced Characterization of Material Properties on the Nanometer Scale Using Atomic Force Microscopy

Near-field microwave imaging of inhomogeneous KxFeySe2: Separation of topographic and electric features

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